Carburetor



' Jqly 12, 1932. w g, CARTER I 1,866,543

CARBURETOB Original Filed Dec. 23. 1929 Patented July 12, 1932 UNITED STATES 'WILLIAM G. CARTER, OF FLINT, MICHIGAN CARBURETOR Original application filed December 23, 1929, Serial No. 415,995. Divided and't his applicationfllod November 21, 1930.

This application is a divisionof my pending application for patent for improvements in carburetors, Serial No. 15,995, filed December 23, 1929, and relates to a novel fuel duct or passageway through which liquid fuel is conveyed from a source of supply to the main passageway of the carburetor at a point in proximity to the edge of the throttle valve when said throttle valve is closed or only partly open.

One object of my present invention is to simplify the construction and reduce the cost of manufacture of a carburetor equipped with a fuel supply duct or passageway of the type mentioned.

Another object is to provide a carburetor which is of such design that an adequate supply of fuel is assured for an idle speed fuel supply duct that discharges into the main passageway of the carburetor adjacent the throttle valve, and an adequate supply of fuel is also assured for an accelerating well or reservoir, from which fuel is conducted into the main passageway of the carburetor under certain operating conditions.

Figure 1 of the drawing is a vertical sectional view of a carburetor embodying my present invention. f V

Figure 2 is a top plan View of the float chamber casting, showing the horizontally disposed plate that forms the top side of certain passageways formed in the upper face of the top wall of the float chamber. Figure 3 is a vertical sectional view of the float chamber casting, taken at substantially right angles to Figure 1 on the line 33 of Figure 2.

Figure 4 is a horizontal sectional view, taken on the line -l4 of Figure 3, looking in the direction indicated by the arrows.

Figure 5 is a perspective view of the adjustable member that formspart of the upper portion of the idle feed fuel supply duct that delivers fuel to the main passageway of the carburetor adjacent the edge of the throttle valve.

Figure 6 is a rear elevational View of said adjustable member, i. e.,-a view looking at the rearside of said member, which is presented to the back wall of the open-sided Serial No. 497,195.

grolove in which said member is positioned; anc

Figure 7 is a cross-sectional view of said adjustable member, taken onapproximately the line 7-7 of Figure 6, looking in the direction of the arrow in Figure 6, but showing said member positioned in its groove;

Referring tothe drawing which illustrates the preferred form of my invention, 00 A designates the main passageway of the carburetor, which is herein illustrated as being formed by a vertically-disposed bore in a casting 1 that constitutes the main body of the carburetor, B designates a throttle valve of the oscillating type arranged adj a cent the upper end of said main passageway, C designates a main air chamber in the body casting 1, provided with a tubular inlet 2 to which a conventional air cleaner can be connected, if desired, and D designates a choking member of. Venturi form that is adapted to be moved downwardly into engagement with a horizontally-disposed plate- 4 at the bottom of the main chamber 0, so as to prevent air from passing from the chamber G directly into the lowerend of the choking member D.

The float chamber E is formed bya casting that is arranged under the bodycasting e0 1 and combined with same in any preferred or suitable way. As shown in Figure 1,

the float chamber E is of annular form and is provided with a horizontally-disposed top wall 12 that is integrally connected to a cylindrical outer wall 13 audi a cylindrical inner wall 14,'sai-d outer and inner walls being arranged in concentric relation. A vertically-disposed web F, which is arranged transversely of the space inside of the cylindrical inner wall 14, as shown in Figure 4, is used to form a number of passages and also as a support for atubular member G that projects upwardly 1 into the choking member D. As shown in the drawing, the center web F of the float chamber casting is provided with a bulged central portion, as shown in Figure 4, that co-operates with the cylindrical wall 14 inside of whi h it is arranged, to form an accelerating yell or 199 reservoir H that is adapted to receive liquid fuel, the upper end of said reservoir or accelerating well H communicating with air passages 15 formed in the top wall 12 of the float chamber, as shown in Figure The horizontally-disposed plate 4, previously referred to, against which the bottom edge of the choking member bears when said choking member is in its fully closed position, forms the top wall of the air passages 15, just mentioned, and the peripheral edge of said plate 4 is spaced away from the side walls of the recesses in the top of the float chamber that constitutes the air passages 15, so that air can flow freely from the main air chamber C of the carburetor into the air passages 15, and thence downwardly into the accelerating reservoir H, as indicated by the, arrows w in Figure 3. At the lower end of the web F is a center bore or space which forms part of the accelerating well H, and at the upper end of said center bore is a horizontally-disposed wall or partition 17 which an orifice 18 is formed at a point in longitudinal alignment with the tubular member G, so as to permit fuel and air to shown in broken lines in Figure 2.

pass from the reservoir H upwardly through said tubular member Gr. Vertically-disposed slots 19 are formed in the portions of the web F that are positioned in the accelerating reservoir H so as to permit the air which flows downwardly into said accelerating reservoir H to travel inwardly to the center bore atthe lower end of the web F, and .thence flow upwardly through the orifice 18, the slots 19 being so positioned that the normal level of the fuel in the accelerating well H will be a trifle below the upper ends of the slots '19,. as indicated by the dot and dash line in Figure 1. 4

The top' wall 12 of the float chamber is alsoprovided with two additional passages 20 and 21 that have no communication with each other, and no communication with the air passages 15 previously mentioned. These separate passages '20 and 21 are arranged radially with respect to the center tubular member G of the carburetor and are disposed diametrically opposite each others, as

aid passages20 and. 21 are produced by forming recesses in the upper surface of the top wall 12 of the float chamber and using the plate 4: as a closure for said recesses. One of ti e said passages, to wit, the passage 20, is used to admit air under certain conditions to air ports 22 formed in the lower end of the tubular member G at a point just above the orifice 18 in the partition plate 17 at the upper end of the accelerating reservoir H, the inner end of said air passage 20 communicating with a vertically-disposed passage 23 that is formed in the web F. As shown in Figures 1 and 4, this passage 23 communicates at its upper end with the horizontallydisposed air passage 20, and the lower end portion of said passage 23 c'ommunicates with the main full supply means of the carburetor, which is herein illustrated as consisting of a fuel supply device I provided with an orifice through which fuel passes from the float chamber of the carburetor into the lower end of the passageway 23. The accelerating reservoir H receives its supply of fuel fromthe passageway 23, through a duct 24 that leads laterally from the passage 23 and discharges into the accelerating reservoir H, as shown in full lines in Figure 1 and in dotted lines in Figure 4. Under certain operating conditions, for example, when the motor is operating under a load and with the throttle valve set in its open position, air is drawn from the main air chamber C down through the accelerating reservoir H, by way of passages 15, which air, in passing through the reservoir H, picks up fuel in said reservoir and carries said fuel upwardly through the orifice l8 and tubular member G into the main passageway of the carburetor.

The passage 21 in the top of the float chamber is used to form part of an idle feed fuel supply duct through which fuel is introduced into the main passageway of the carburetor at a point in proximity tothe peripheral edge of the throttle valve at idle speeds of the motor. cates at its inner end with a vertically-disposed bore 33 in the web F of the float chamber casting, said bore leading upwardly from a space that holds liquid fuel. Said space is herein illustrated as consisting of a shat low annular reservoir K formed in the bottom end of the web F. The outer end of the. passage 21 communicates with a fuel tube 34 that is arranged vertically in the body casting and which forms part of the idle feed fuel supply duct previously mentioned.

The upper end portion of said idle feed fuel supply duct is constructed in such a way that it can be adjusted to accurately position the fuel discharge orifice of said duct relatively to the throttle valve of the carburetor when the carburetor is being installed on the engine on which it is used. One object of my present invention is to simplify the construction and reduce the cost of manufacture of the upper end portion of said idle feed fuel supply duct. Preferably, the upper end portion of the duct in question is formed by a vertically-disposed bar-like member 35 of substantially rectangular shape in cross section, shown in Figure 5,- that is positioned in an open-sided verticallydisposed groove formed in the side wall of the main passageway A. The groove in which the member 35 is positioned is also of rectangular shape in cross section and one of the inner corners of the member 35 is beveled at 36, as shown in Figures 6 and 7. Consequently, when said member 35 is arranged in Said passageway 21 communioperative position in its receiving groove, there will be a fuel duct or passageway between the beveled corner 36 of the member 35 and the groove in the body casting in which said member is positioned, said duct having a lateral outlet leading into the main passageway A adj acent the edge of the throttle valve.

l/Vhile I prefer to use a bar or member 35 of.

substantially square cross section, and arrange said member in an open-sided groove formed vertically in the body casting l at one side of the main air passageway A, it is not absolutely essential that the member 35 and the groove in which it is positioned be of the particular cross-sectional shape herein shown. The essential thing, so far as this featureof my invention is concerned, is that the upper end portion of the idle feed fuel supply duct of the carburetor be formed by co-acting portions on the body casting and on a solid or substantially bar-like member positioned in said casting and having a portion of its surface shaped so that it will be spaced away from the body casting to constitute a duct or fuel passageway. The lateral outlet'leading from the said duct may be formed by a notch or groove 37 formed in one side of the member 35, as shown in Figure 6. 5

Means is preferably provided for raising and lowering the member 35 in order to adjust or accurately position the fuel discharge orifice of said duct relatively to the throttle valve B when the carburetor is being installed on the engine on which it is used. Various means may be provided for this purpose, such, for example, as an adjusting screw 38 mounted in the body casting 1 and provided at its inner end with an eccentrically-disposed pin 39 that is positioned in a transversely-disposed slot 4:0 formed in the inner face of the member 35 that is presented to the back wall of the groove in which the member 35 slides, said slot being shown in broken lines in Figure 5, and in full lines in Figure 6. Due to the fact that the slot 40 extends transversely of the member 35 and is of considerably greater length than the diameter of the eccentrically-disposed pin 39 on the adjusting screw 38, said pin 39 is capable of moving laterally in the slot 40 when the adjusting screw 38 is rotated to raise or lower the member 35. The adjusting screw 38 is held in its adjusted position by a spring-pressed plunger 38 Any suitable means may be used to retain the member 35 in the groove in the body casting in which said member is positioned, the means herein illustrated for this purpose consisting of a horizontally-disposed split expansion ring 41 (see Figure 1) arranged in the side wall of the main passageway A in such a manner that it will engage themember 35, and thus securely hold said member in the groove in which it is positioned;

In order, to assure an adequate supply of fuel for the fuel chamber K from which the idle feed fuel supply duct leads, andalsoan adequate supply of fuel for .the accelerating reservoir'H .of the carburetor, I- have pro: vided the carburetor with two; separate and distinct means for supplying fuel tothe fuel chamber K and to the acceleratingreservoir H. As previously described, the accelerating reservoir H receives its'supply of fuel from V Under some oneratin conditions as for example, when the motor is operatingunder a load and with the throttlevalve set in its open position, air is drawn from the main air chamber: G down through-the accelerating reservoir H, by way ofpassages 15, with the result that more or less ofthe fuel in said reservoir :will bepicked up by the flowing air and carried upwardly, first, through the orifice 18, and then through the tubular member G, into the main passageway of the/carburetor. At idling speeds fuel is introduced into the main passageway above the throttle valve by the idle feed fuel supply duct which leads from the shallow fuel chamber K. It is not absolutely essential that separate and distinct fuel supplying devices or passages be provided for delivering fuel to the shallow chamber K and to the accelerating reservoir H, although I prefer to construct the car buretor in this manner, as it insures an adequate supply of fuel for. the fuel ductthat discharges into the main passageway above the throttle valve in instances where the motor is idling, but is operating at such a speed as to keep the accelerating reservoir H dry or substantially so.

Having thus described my invention,'what I claim as new and desire to secure by Letters Patent is 1. A carburetor provided with 'a'main pas-i formed by co-acting surfaces in a groove in v oneside of said main passageway and a barlike member positioned in said groove.

2. A carburetor provided with a main passageway having a. groovein the side wall of same, and a member in said groove having a portion of its surface spa-ced'away from the wall of said groove, so as to form a fuel duct.

3. A carburetor provided with a main passageway, a groove in the side wall of said passageway that is of substantially rectangular shape in cross section, and a member of substantially rectangular shape in cross sectiompositioned in said groove and having a portion. of. its surface cutaway so as to produce a fuelduct. that has a 'lateraldischarge outletileading to said main passageway.

' 4. Ina carburetor,a main passageway provided with; a throttle valve, and a duct leading from a supply of fuel for introducing fuel into said passageway adjacent the throttle valve, the upper end portion of said duct being formed by co-acting surfaces on a groove and a member positioned in said groove, and means for enabling said member to be adjusted to vary the relationship between-the discharge end of said duct and said throttle valve. i

5; In a carburetor, the. combination of a main passageway, a throttle valve in said passageway, an open-sided groove formed in the side wall of said passageway and disposed vertically, a bar-like member in said groove having a portion of its surface cut away so asto form a fuel duct, means for adjusting said member, and means for preventing said member from becoming bodily displaced from said groove.

- WILLIAM C. CARTER. 

